In the Linux kernel, the following vulnerability has been resolved:
iouring/kbuf: hold iobuffer_list reference over mmap
If we look up the kbuf, ensure that it doesn't get unregistered until after we're done with it. Since we're inside mmap, we cannot safely use the iouring lock. Rely on the fact that we can lookup the buffer list under RCU now and grab a reference to it, preventing it from being unregistered until we're done with it. The lookup returns the iobuffer_list directly with it referenced.